抄録
Transport of α-aminoisobutyric acid (AIB) by membrane vesicles from virally transformed and nontransformed cells was analyzed under various assay conditions. Trypsin treatment or the addition of 100 mM NaSCN for driving force resulted in the generation of a transient concentrative uptake of AIB (overshoot) by nontransformed cell membranes, although the shape of the overshoot differed from that of transformed cell membranes in the same conditions of transport assay. Thus, the overshoot is not a specific phenomenon for transformed cell membranes. Furthermore, at the low temperature (5°) of assay incubation, the pattern of AIB transport by transformed cell membranes resembled that by nontransformed cell membranes in the slow initial rate of uptake and prolonged overshoot. Therefore, in the mechanism. for AIB transport, there may be no fundamental differences between transformed and nontransformed cell membranes.
